Multi-axial thermo-mechanical analysis of power plant components from 9–12% Cr steels at high temperature

2011 ◽  
Vol 78 (8) ◽  
pp. 1657-1668 ◽  
Author(s):  
Konstantin Naumenko ◽  
Andreas Kutschke ◽  
Yevgen Kostenko ◽  
Thorsten Rudolf
Keyword(s):  
High Temperature ◽  
Power Plant ◽  
Mechanical Analysis ◽  
Cr Steels ◽  
Plant Components

Online Creep-Fatigue Monitoring of Cyclic Operation in a Coal-Fired Power Plant

2017 ◽  
Author(s):  
Stan T. Rosinski ◽  
Kent Coleman ◽  
Mario Berasi ◽  
Curt Carney ◽  
Ulrich Woerz ◽  
...  
Keyword(s):  
High Temperature ◽  
Power Plant ◽  
Fatigue Damage ◽  
Power Plants ◽  
Transfer Functions ◽  
Stress Transfer ◽  
Operating Conditions ◽  
Element Analysis ◽  
Thermal Transients ◽  
Plant Components

Coal-fired power plants are often required to cycle extensively and operate relatively infrequently due to power market conditions and an increasingly broad deployment of renewable energy. This cyclic (start-stop and/or fast ramp rate) operation can result in accumulation of fatigue damage, particularly in thick-walled components such as high temperature headers that experience the greatest thermal transients. In addition, components exposed to high temperature and pressure experience creep damage over time. Tracking the accumulation of creep and fatigue damage can aid in life management of these components. EPRI developed the Creep-FatiguePro™ system to monitor the accumulation of creep and fatigue damage in plant components while considering component geometry and the ongoing changes in operating conditions (temperatures, pressures and flow rates). The software requires a configuration process to define stress transfer functions for damage analysis and often involves performing a finite element analysis for each component geometry. Although accurate, this process can be time-consuming, especially if a large number of components are to be monitored. In a recent application of this system at the As Pontes power plant in Spain, a simple closed form analytical solution was used in the configuration process in order to more rapidly obtain the stress transfer functions. For direct interaction with the plant’s data historian, the software was also modified to support connection to the plant data system. Results using the two configuration approaches will be compared and recommendations made for future use in monitoring creep and fatigue damage in power plant components.

scholarly journals Accelerated Creep Life Assessment of In-Service Power Plant Components

2019 ◽  
Vol 293 ◽  
pp. 03001
Author(s):  
Saud Hamad Aldajah ◽  
Mohammad Mazedul Kabir ◽  
Mohammad Y. Al-Haik
Keyword(s):  
High Temperature ◽  
Power Plant ◽  
Structural Integrity ◽  
Elevated Temperatures ◽  
Sem Analysis ◽  
Life Assessment ◽  
High Temperature Creep ◽  
Creep Life ◽  
Temperature Creep ◽  
Plant Components

Structural metals used in plant components are subject to aging from a combination of fatigue, creep, and corrosion. Exposure to elevated temperatures promotes creep. Aged metals lose toughness, or the ability to absorb energy at stress above the yield point and cannot endure an occasional high load without fracturing. Creep is one of the most critical factors for determining the structural integrity of components. The main objective of the current study is to assess the remaining creep life of various 20-year old power plant engineering components such as the high temperature fasteners. Due to time constraints, the approach followed in this study was to utilize the accelerated high temperature creep testing in addition to Scanning Electron Microscopy (SEM) analysis to assess the remaining life of 4 different samples. The accelerated high temperature creep tests were conducted at a stress level of 61 MPa and at a temperature of 1000°C for samples Sample 1 (original), Sample 2, Sample 3 and Sample 4; these samples were collected from different parts of the power plant. SEM analysis was carried out for all the samples. The results of the accelerated high temperature tests were compared to similar materials’ theoretical creep data using Larson Miller curve. The Larson Miller actual creep lives of the tested samples were much higher than the experimental ones, which suggest that the samples are critically aged. SEM analysis on the other hand, showed that all samples have high percentage of creep voids

Evolving Design Methods for Modern High Temperature Power Plant Components

2016 ◽  
Author(s):  
Ian Perrin ◽  
Jonathan Parker
Keyword(s):  
High Temperature ◽  
Power Plant ◽  
Design Guidelines ◽  
Structural Behavior ◽  
Comprehensive Review ◽  
Material Response ◽  
Design For Safety ◽  
Analysis Design ◽  
Current Code ◽  
Plant Components

This paper summarizes recommendations made as part of the work considering modernization of ASME Section I (Power Boilers). It is not intended to provide a comprehensive review of issues regarding design guidelines for components. However, to introduce the context of the approaches that are recommended, background is provided on a number of topics related to Design-By-Analysis, Design-By-Formula, Design-For-Safety and Design-For-Lifetime. Benefits, shortcomings or inconsistencies associated with particular approaches are discussed. It is apparent that no one current Code or Standard has a method that can be universally adopted. This paper outlines the features of a Design-By-Analysis approach that is both relevant, technically consistent and which considers the key modes of structural behavior and material response.

Robust Methods for Creep Fatigue Analysis of Power Plant Components Under Cyclic Transient Thermal Loading

2013 ◽  
Author(s):  
Yevgen Kostenko ◽  
Henning Almstedt ◽  
Konstantin Naumenko ◽  
Stefan Linn ◽  
Alfred Scholz
Keyword(s):  
High Temperature ◽  
Power Plant ◽  
Constitutive Model ◽  
Thermal Loading ◽  
Hold Time ◽  
Local Stress ◽  
Life Assessment ◽  
Heat Transfer Analysis ◽  
Turbine Component ◽  
Plant Components

The aim of this paper is to apply robust mechanisms-based material laws to the analysis of typical high-temperature power plant components during an idealized start-up, hold time and shut-down sequence under a moderate temperature gradient. Among others a robust constitutive model is discussed, which is able to reflect inelastic deformation, hardening/recovery, softening and damage processes at high temperature. The model is applied for a creep analysis of advanced 9–12%CrMoV heat resistant steels and calibrated in particular case against experimental data for 10%CrMoV steel type. For a steam temperature profile transient heat transfer analysis of an idealized steam turbine component is performed providing the temperature field. From the subsequent structural analysis with the inelastic constitutive model local stress and strain state variations are obtained. As an outcome a multi-axial thermo-mechanical fatigue (TMF) loading loop for one or several loading cycles can be generated. They serve as input for a fatigue life assessment based on the generalized damage accumulation rule, whose results come close to reality. In addition, the accuracy of a simplified method which allows a rapid estimation of notch stresses and strains using a notch assessment rule (NAR) [1] based on Neuber approach is examined.

Human reliability in non-destructive inspections of nuclear power plant components: modeling and analysis

2019 ◽  
Vol 7 (2B) ◽  
Author(s):  
Vanderley Vasconcelos ◽  
Wellington Antonio Soares ◽  
Raissa Oliveira Marques ◽  
Silvério Ferreira Silva Jr ◽  
Amanda Laureano Raso
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Human Factors ◽  
Nuclear Power ◽  
Power Plants ◽  
Failure Modes ◽  
Cooling System ◽  
Human Reliability ◽  
Non Destructive ◽  
Plant Components

Non-destructive inspection (NDI) is one of the key elements in ensuring quality of engineering systems and their safe use. This inspection is a very complex task, during which the inspectors have to rely on their sensory, perceptual, cognitive, and motor skills. It requires high vigilance once it is often carried out on large components, over a long period of time, and in hostile environments and restriction of workplace. A successful NDI requires careful planning, choice of appropriate NDI methods and inspection procedures, as well as qualified and trained inspection personnel. A failure of NDI to detect critical defects in safety-related components of nuclear power plants, for instance, may lead to catastrophic consequences for workers, public and environment. Therefore, ensuring that NDI is reliable and capable of detecting all critical defects is of utmost importance. Despite increased use of automation in NDI, human inspectors, and thus human factors, still play an important role in NDI reliability. Human reliability is the probability of humans conducting specific tasks with satisfactory performance. Many techniques are suitable for modeling and analyzing human reliability in NDI of nuclear power plant components, such as FMEA (Failure Modes and Effects Analysis) and THERP (Technique for Human Error Rate Prediction). An example by using qualitative and quantitative assessesments with these two techniques to improve typical NDI of pipe segments of a core cooling system of a nuclear power plant, through acting on human factors issues, is presented.

ALLEGHENY LUDLUM AL276

Alloy Digest ◽  
1996 ◽  
Vol 45 (1) ◽  
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Power Plant ◽  
Physical Properties ◽  
Surface Treatment ◽  
Tensile Properties ◽  
Crevice Corrosion ◽  
Heat Treating ◽  
Chemical Plants ◽  
Temperature Performance

Abstract Allegheny Ludlum AL276 is widely used in the most severe environments found in chemical plants and in power plant desulfurization systems. The high molybdenum level with tungsten gives excellent pitting and crevice corrosion resistance. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on low and high temperature performance, and corrosion resistance as well as forming, heat treating, joining, and surface treatment. Filing Code: Ni-497. Producer or source: Allegheny Ludlum Corporation.

scholarly journals Effects of Ni Additions on the High Temperature Expansion, Melting and Oxidation Behaviors of Cobalt-Based Superalloys

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 173
Author(s):  
Patrice Berthod ◽  
Lionel Aranda ◽  
Jean-Paul Gomis
Keyword(s):  
Thermal Expansion ◽  
High Temperature ◽  
Mechanical Analysis ◽  
Scanning Calorimetry ◽  
Beneficial Effects ◽  
Ni Addition ◽  
High Temperature Expansion ◽  
High Fraction ◽  
Thermal Analysis Techniques ◽  
Ni Additions

Nickel is often added to cobalt-based superalloys to stabilize their austenitic structure. In this work the effects of Ni on several high temperature properties of a chromium-rich cobalt-based alloy reinforced by high fraction of TaC carbides are investigated. Different thermal analysis techniques are used: differential scanning calorimetry (DSC), thermo-mechanical analysis (TMA) and thermogravimetry (TG). Results show that the progressive addition of nickel did not induce great modifications of microstructure, refractoriness or thermal expansion. However, minor beneficial effects were noted, including reduction of the melting temperature range and slight decrease in thermal expansion coefficient. The most important improvement induced by Ni addition concerns the hot oxidation behavior. In this way, introducing several tens wt % Ni in this type of cobalt-based alloy may be recommended.

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